Further Notes on British Orihatidse. By A. D. Michael. 15 



formed. The ceplialothorax bears a complicated series of ridges 

 not easy to describe, and whicli will be best understood by reference 

 to the drawing. I will, however, endeavour to give an idea of their 

 arrangement in words. The median (or axial) portion of the 

 vertex is divided into three spaces bordered by strong raised ridges. 

 The anterior one is trapeze-shaped, with the small end foremost and 

 coming near to the point of the rostrum, but not reaching it. Two 

 short ridges, however, run from the anterior angles of the trapeze, 

 one to each side of the rostrum, very near to the point. The ridge 

 which forms the posterior border of the trapeze forms the anterior 

 border of a hexagon, which has curved sides, convex inwards, the 

 anterior side being the longest, and the two next sides very short. 

 The posterior ridge of the hexagon forms the anterior margin of an 

 oblong or elliptical figure, usually somewhat constricted in the 

 middle. This figure extends back on to the abdomen, so that it is 

 difficult to say where the abdomen commences in the median line. 

 From the central angle on each side of the hexagon a short trans- 

 verse ridge runs about half-way towards the lateral margin. From 

 its termination a ridge runs forward to the front of the excavation 

 for the first leg, and another, or continuation of the same, runs 

 back to a circular ridge surrounding the stigma, and from the stigma 

 a triangular space bordered by another ridge extends to the lateral 

 margin. The stigmatic organs are short, globular, on a short 

 peduncle, and very white. The interstigmatic hairs are absent or 

 little seen ; the rostral hairs are present. 



The legs are stout and gradually diminished towards the end. 

 The third and fom-th joints of the two front pairs each bear a strong 

 serrated spine on the upper side ; the other hahs on the legs are 

 short, and the tactile hair is absent. 



The abdomen is flat in general effect, but has somewhat raised 

 anterior and lateral edges, and is raised to about the same extent 

 along the median portion, being slightly arched there ; between 

 this median portion and the lateral edge is a depressed channel. 

 The whole abdomen is covered with wavy closely-set irregular 

 wrinkles. Three or four of these run along the anterior, and about 

 half-way down the lateral margin ; the centre of the space enclosed 

 by these last-named wrinkles is occupied by a set of wrinkles 

 bending strongly forward. Behind them the wrinkles become 

 more transverse, until near the posterior margin, where they again 

 bend strongly forward. The posterior margin is set with eight 

 spatulate hairs, of which the two lateral pairs are very short, the 

 two central pairs much longer and directed inward, the central pair 

 crossing. 



I have only found the species on the Uchen near the sea-shore, 

 at the Land's End, Cornwall. It has not to my knowledge been 

 recorded before I found it, and it is not common. 



